Genetic screening and fertility tests based on bovine semen biomarkers

• Grant number: 21/13062-0
• Support Opportunities: Scholarships abroad - Research
• Start date: April 01, 2022
• End date: March 31, 2023
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Mayra Elena Ortiz D' Avila Assumpcao
• Grantee: Mayra Elena Ortiz D' Avila Assumpcao
• Host Investigator: Peter Sutovsky
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: University of Missouri, Columbia (UM), United States

Abstract

With climate change, fires, floods, global warming are part of our daily lives. One of the factors responsible for the situation in which the world finds itself, pointed out at COP26 in Glasgow last month, is livestock. However, it is not enough to blame a sector and demand that the consumer no longer eat meat, especially beef. It is necessary for each sector to think about solutions and alternatives to improve this situation. Thinking about my area of expertise, which is beef production, the next question is what can I do? What research should be done for this scenario to improve. The answer lies in improving reproductive efficiency. Having bulls in the plants that will be infertile or subfertile is an unnecessary emission of methane. Until these bulls are able to breed, it takes years to complete all fertility tests. We must focus our studies on the selection and prediction of these animals. In previous studies, genetic mutations associated with high and low fertility of bulls have been identified through complete genome sequencing and genome-wide association analysis. The main focus is on homozygous recessive single nucleotide polymorphisms (SNPs) that impact sperm phenotype in homozygous mutants. However, when the bull carries a heterozygous mutant allele, this mutation may not affect fertility, but it is sufficient to spread such harmful alleles in the gene pool propagated by AI. The hypothesis of this project is that differences in the fertility rates of bulls that pass the reproductive health assessment are due to a relatively small number of identifiable polymorphisms in key genes that affect spermatogenesis, sperm function, and early embryonic development. The research objective is to evaluate associated sperm phenotypes and their overall impact on sperm morphology, protein structure, function and localization using high-throughput multiplex flow cytometry, including sperm, zinc, proteomics, and cell imaging fluorometry.Assisted reproduction techniques (ART) are an integral part of the livestock industry, increasing the effect of breeding programs based on genomic selection, improving reproductive performance, genetic gain and general efficiency. These techniques associated with genomic selection will bring a greater contribution and better reproductive and productive efficiency. (AU)